Analysis of energy saving routes for sewage treatment systems based on flexibility theory

In order to find out more effective energy saving strategies for sewage treatment systems, the necessity of endowing a sewage treatment system with certain extent flexibility were analyzed based on the summarization of current major energy saving measures responding to the changing conditions, such as variations of quality and flux of input sewage. Furthermore, the routes of saving energy for sewage treatment processes were discussed based on flexibility theory. The results show that more energy saving measures could be detected through studies on flexibility, and that process synthesis and improving flexibility of treatment system are effective ways to increase the energy saving potential of sewage treatment systems. The results also show that the energy saving potential can be transformed into a realizable form by increasing the control power of the controlling systems of sewage treatment systems as well as improving the flexibility of management and organizational structures of sewage treatment enterprises.